Nanoclay- and TiO2 Nanoparticle-Modified Poly(N-vinyl pyrrolidone) Hydrogels: A Multifunctional Material for Application in Photocatalytic Degradation and Adsorption-Based Removal of Organic Contaminants

In recent times, access to clean water has become increasingly difficult and one of the most important problems for the sustainability of life due to environmental pollution. Based on this thought, in this study, a multifunctional hydrogel nanocomposite (nanoclay@TiO2@PNVP) containing linear poly(N-vinyl pyrrolidone) (PNVP), nanoclay, and TiO2 nanoparticles was synthesized and used as an adsorbent and photocatalyst for the adsorption-based and photocatalytic degradation-based removal of organic and pharmaceutical pollutants such as methylene blue (MB) and sildenafil citrate (SLD). The modification of the hydrogel with TiO2 nanoparticles and nanoclay aimed to increase the adsorption capacity of the PNVP hydrogel as well as to gain photocatalytic properties for the effective removal of organic contaminants. This hybrid material, which can be cleaned in two different ways, can be reused and recycled at least 10 times. Characterization studies were carried out using Fourier transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy, thermogravimetric analysis, differential thermogravimetry, and viscosimetry techniques. Optimization studies for the adsorption-based removal of organic contaminants were carried out on MB and SLD as model organic compounds. The optimum parameters for MB were found at pH 10 of the sample solution when 50 mg of the nanoclay@TiO2@PNVP hydrogel nanocomposite was used for 420 min of contact time. It was observed that 99% of the MB was photocatalytically degraded within 150 min at pH 10. Our material had multifunctional applicability properties, showing high adsorption and photocatalytic performances over 99% for at least 10 times of use. For the removal of organic and pharmaceutical contaminants from wastewater, the synthesized material can be used in two treatment processes separately or in combination in one step, providing an important advantage for its usability in environmental applications

Synthesis, characterization and X-ray structures of tetrathiafulvalene-type electron donors bearing one pyridine group

International audienceMono-pyridyl tetrathiafulvalene derivatives have been synthesized by thiolate deprotection-alkylation procedure. Spectroscopic characterization is given as well as their electrochemical properties. Their redox potentials have been studied by cyclic voltametry. As expected, the molecules with m-pyridyl ring are easier to oxidize than molecules with same substituents, bearing p-pyridyl ring. Nine compounds were recrystallized; their structures are presented and discussed. One complex from one molecule of these series was obtained by anodic oxidation method; its synthesis and structure are given

Synthesis, Characterisation, Hirshfeld surface analysis, Magnetic susceptibility, DFT calculations, pkCSM profile, and Biological activities of Novel mono‐, di‐, and multinuclear Cobalt (II) complexes

International audienceThis study explores the synthesis and diverse properties of newly synthesised water‐soluble cobalt (II) complexes (1‐3). Analysis of the complexes through various methods, including Hirshfeld surface analysis, reveals distinctive intermolecular interactions, particularly robust H‐bonding contributions to crystal packing. 2D fingerprint plots provide quantitative insights into supramolecular interactions, while TGA‐DSC analysis elucidates multi‐step decomposition processes, mainly involving organic moieties. FT‐IR and SCXRD confirm the structures of the complexes. Magnetic susceptibility measurements show paramagnetic behaviour in all complexes. FMO calculations expose HOMO‐LUMO gaps and charge transfer processes, with NBO analysis emphasizing the significance of chloride, nitrogen, and oxygen atoms in coordination. In addition, pkCSM profile was carried out. The biological properties of the complexes reveal potent antibacterial activity for 2 and 3 against Gram‐positive and Gram‐negative bacteria. Despite lower antibacterial efficacy compared to standard antibiotics, their water solubility suggests potential human pharmacological applications. In terms of anti‐inflammatory activity, all three complexes exhibit concentration‐dependent prevention of ovalbumin denaturation, with 2 being the most effective. Compound 3, despite having seven carboxyl groups, exhibits the weakest anti‐inflammatory effect, potentially attributed to complex formation obscuring these groups. Furthermore, all complexes display antioxidant activities; 1 and 2 are greater than BHT in the ferric thiocyanate assay

Synthesis, Antimicrobial, DFT, and In Silico Pharmacokinetic Profiling of Nitroaldol Quinoline Derivatives: A Comprehensive Exploration for Designing Potential Oral Antibacterial Agents Targeting DNA-Gyrase

International audienceThis study presents a thorough exploration of the synthesis, biological activities, and molecular properties of a novel series of nitroaldol quinoline derivatives (4a-4i). Structural characterization utilized FTIR, mass spectrometry, 1H NMR, and 13C NMR, providing a comprehensive understanding of the synthesized derivatives. Moreover, anti-microbial properties were evaluated using agar disk diffusion assay against five pathogenic strains, including Gram-negative and Gram-positive bacteria, as well as a fungal strain. Notably, compound 4e demonstrated strong anti-fungal and anti-bacterial activities (MIC = 25 µg/ml). A detailed analysis of molecular orbitals, total density of state, vibrational characteristics, global reactivity descriptors, molecular electrostatic potential, topological QTAIM analysis, and molecular docking provided nuanced insights into the reactivity, electronic properties, and potential interactions of the synthesized compounds. These findings contribute valuable information to the design and synthesis of compounds targeting bacterial DNA-gyrase. Furthermore, in silico predictions using the SwissADME online server indicated that all compounds comply with Lipinski's rule of five, suggesting their potential as orally active drugs. The compounds demonstrated commendable water solubility, passed various filters, and exhibited bioavailability scores, indicating promising oral bioavailability. The percentage of oral absorption ranged from 75.39% to 78.58%, signifying high permeability. Computational analysis of pharmacokinetic parameters revealed favorable characteristics, including gastrointestinal absorption and minimal inhibitory effects on specific enzymes

Combined experimental, computational studies (synthesis, crystal structural, DFT calculations, spectral analysis) and biological evaluation of the new homonuclear complexDi-µ-benzoato-bis [benzoatodipyridinecobalt (II)]

International audienceA binuclear cobalt(II) benzoate complex with pyridine as auxiliary ligands has been synthesized and identified by UV–Vis, IR spectroscopy, and TG-DTA analysis. The molecular structure of the complex was determined by single-crystal X-ray diffraction (SCXRD). Thermogravimetric analysis shows two steps decomposition of the present complex. The Co (II) ions are in a distorted octahedral environment [CoN2O4]. The crystal structure was stabilized by different intramolecular/ intermolecular interactions, including Van der Waals, hydrogen bonding, donor-acceptor, and π-π interactions between the pyridine rings. Furthermore, all density functional theory (DFT) calculations have been performed in the gas phase using the GGA-BLYP functional and the TZP basis set, and for the Time-Dependent Density Functional Theory (TD-DFT) calculations, several functionals have been used, namely the GGA BLYP and PBE, the hybrids B3LYP and PBE0, the SAOP potential model, and finally the range-separated CAMY-B3LYP functional with the TZP basis set. Good consistency was observed between the calculated and the experimental results. The bond dissociation energies (BDE) were calculated using the fragment analysis. The intermolecular interactions were investigated through the Molecular Electrostatic Potential (MEP) and supported by Hirshfeld charges analysis. To characterize the non-covalent interactions in the complex, (NCI plot) index has been computed and supported by AIM analysis. Also, the global and local reactivity descriptors have been calculated to highlight the reactive sites in the molecular structure. Moreover, the antimicrobial activity was evaluated by agar disk diffusion assay against seven pathogenic strains, and the antioxidant activity was estimated using four different techniques. In addition, the in vitro anti-inflammatory activity was assessed by the albumin denaturation method

Co(II)-Co(II) Paddlewheel Complex with a Redox-Active Ligand Derived from TTF

International audienceA new trimethyltetrathiafulvalene (Me3TTF) derivative Me3TTF-CH=CH-py bearing a pyridyl was synthesized and coordinated to a cobalt(II) benzoate dimer, having paddlewheel core structure, leading to a complex formulated as Co2(PhCOO)4(Me3TTF-CH=CH-py)2. Single-crystal X-ray diffraction studies of the complex performed at 293 and 100 K evidenced the existence of a weak metal-metal interaction. Magnetic studies revealed an antiferromagnetic behavior, which is explained as the result of the direct exchange between metal centers